Batios



:T Patented Aug. 13, 1929.

lTE STATE OFFICE,

AN OWRUMISLENSKY, 013 NEW YURK, N. Y-, .ASMIGNUR TU THE PYRIDIUM llURPCW- MTION, Uh NEW YURK, N. "iii, A CORPUJRA'I'IUN DI" NEW YORK.

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This invention is an improvement in methods of preparing water soluble azo dyes, and more particularly in methods of obtaining phenyl-diazo-amido- (alpha) alpha-monami no pyridine, and the hydrochlorides thereof.

Application riled $cptcmher Q3, 1927. serial No. $21,628.

sucient to boil the given hydrochloride with pure distilled water for from 5 to 120 minutes, In this time the original hydrochloride dis solves in water and is quantitatively converted into phenyl-azo diarninepyridine hydroa Une of the' primary objects of the present chlorides, or the corresponding azo-amido invention is the provision of a method of preparing a substance which for convenience is designated py-diazo-amino compound, capa' in ble of direct conversion into phenyl-azo-alpha-diamino-pyridine,

When phenvl-diaaonium salts are coupled with alpha-a pha-diaminopyridines, under certain conditions, phenyl-diazo-amido-(alpha) -alpha-monamino pyridine, which for the salre of brevity is hereafter designated pysdiaao-amido compound, is obtained, 'lhis resultis obtained not only when coupling is performed in an aqueous medium acidified with organic acid, such as acetic acid, but

lilrewise when an insuficient amount of mineral acid, such as hydrochloric acid, is used.

The compound appears in fine, prismatic,

yellowish-brown crystals, and dissolves very easily in aniline and in pyridine. Recrystallized from carbon tetra-chloride, it appears in the form of fine light orange red lamellae with a sillry shine. The formula is as follows 00 H E o-o orm-Nat nn-d on The compound is easily converted in reaction with hydrochloric acid to the hydrochloride, which is very dark in color, and takes on a deep violet tint when dissolved in concen- 4L0 trated hydrochloric acid. The hydrochloride decomposes readily not only under the action of water, and even from humidity in the air, but also in a very weak hydrochloric acid.

'llhe most striking feature of the hydro-- chlorides of the py-diazoamido compound is the excessive facility With which they ate converted to the corresponding -azo-amido compound, that is, phenyl-azo-alpha-alphahe diamino-pyridine, For this purpose it is This enables the obtaining of the chemically pure phenyl-azo-alpha-alpha-dialnino-pyridine hydrochloride without losses.

When one gram of phenyldiazoaminomonoaminopyridine 'is boiled with 100 cc. of distilled water, the substance gradually goes into solution, and is simultaneously converted into pure phenyl 'azo dianiino pyridine, with a melting point of 137 C.

When boiled with aniline the hydrochlorides of the diaZo-amido compounds are transformed, quantitatively, to the corre sponding azo-amido compound.

Analogous diazo compounds are easily obtained under the same conditions by coupling alpha-alpha-diaminopyridine with 85 the diazotized homologues and analogues of aniline, such as diazotized toluidines, phenetidine, anisidine, and the like. Analogous with the first and simplest member of the homologue series, the hydrochlorides of all so these salts of diazo-amido compounds are easily converted to the corresponding acoamido compounds under similar conditions, for example, prolonged boiling of the substances in distilled water, aniline, or the like. at The base and its hydroehlorides occur in line crystals in different shades of brown and yel low-brown, or reddish orange.

The phenyl-diazo-amido Qalpha) alphamono-amino-pyridine compound described above is interesting, from the View point of a method of obtaining phenyLazo-alpha-alphadiamino-pyridine hydrochlorides by boiling Water. When ingested by the mouth, it is quieklyand easily converted to phenyl-azoalpha alpha diamino pyridine hydrochlorides by the action of the stomach juices, and the presence of its decomposition products in the patients urine, may be easily proven some five to six hours after the ingestion.

' What isclaimed as new is: 1. As an article of manufacture a phenyldiazo-amino-alpha-monamino-pyridine compound eomprismg in its structure the following grouping 2. As an article of manufacture a phenyldiazo-amino-alpha-monamino-pyridine compound comprising in its structure the following probable grouping sists in reacting phenyl-diazonium-salts with alpha-alpha-diamino pyridines in a Weakly acidified aqueous medium. I

Signed at New York in the county of New York and State of New York this 20th day of Sept. A. D. 1927.

- IWAN USTROMISLENSI Y. 

